Cyclisation of nitrile imides with alkenyl substituents: routes to 1,2-benzodiazepines and cyclopropa[c]cinnolines
Abstract
Treatment of the chloroglyoxylate phenylhydrazones (1) with triethylamine affords 1H-1,2-benzodiazepines and/or 1a,7b-dihydro-1H-cyclopropa[c]cinnolines in substantial yields. Mechanisms are proposed which involve different modes of intramolecular rearrangement of the first-formed nitrile imides (8).